NOI 1.5 43: Mass factor decomposition

Describe

A known positive integer n is the product of two different prime numbers, trying to find the larger prime number.

Input

The input has only one row and contains a positive integer n.

For 60% of data, 6≤n≤1000.
For 100% of data, 6≤n≤2*10^9.

Output

The output has only one row and contains a positive integer p, which is the larger prime number.

Sample input

21st

Sample output

7

Source

The

first problem of the popularization group of NOIP2012

• Fayi

#include <bits/stdc++.h>using namespacestd;intN;intMain () {scanf ("%d",&n); for(intI=2; i<n;i++){if(n%i==0) {printf ("%d", n/i); Break;return 0;}}return 0; }

• Law II

  #include <iostream>#include<cmath>using namespacestd;intMain () {intn,t; CIN>>N; T=sqrt (n);  for(intI=2; i<=t;i++)    {        if(n%i==0) {cout<<n/i; return 0; }     }}

NOI 1.5 43: Mass factor decomposition